Geometrische Repräsentation - Element | |

Geometric Representation Item | |

Item de représentation géométrique |

An IfcGeometricRepresentationItem is the common supertype of all geometric items used within a representation. It is positioned within a geometric coordinate system, directly or indirectly through intervening items.

NOTE Definition according to ISO/CD 10303-42:1992

An geometric representation item is a representation item that has the additional meaning of having geometric position or orientation or both. This meaning is present by virtue of:

- being a Cartesian point or a direction
- referencing directly a Cartesian point or direction
- referencing indirectly a Cartesian point or direction
An indirect reference to a Cartesian point or direction means that a given geometric item references the Cartesian point or direction through one or more intervening geometry or topology items.

EXAMPLE 1 Consider a circle. It gains its geometric position and orientation by virtue of a reference to axis2_placement (IfcAxis2Placement) that is turn references a cartesian_point (IfcCartesianPoint) and several directions (IfcDirection).EXAMPLE 2 Consider a manifold brep. A manifold_solid_brep (IfcManifoldSolidBrep) is a geometric_representation_item (IfcGeometricRepresentationItem) that through several layers of topological_representation_item's (IfcTopologicalRepresentationItem) references poly loops (IfcPolyLoop). Through additional intervening entities poly loops reference cartesian_point's (IfcCartesianPoint).

NOTE Entity adapted fromgeometric_representation_itemdefined in ISO 10303-42.

HISTORY New entity in IFC1.5

# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|

IfcRepresentationItem | |||||

LayerAssignment | IfcPresentationLayerAssignment @AssignedItems | S[0:1] | Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.
| X | |

StyledByItem | IfcStyledItem @Item | S[0:1] | Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. | X | |

IfcGeometricRepresentationItem |

` <xs:element name="IfcGeometricRepresentationItem" type="ifc:IfcGeometricRepresentationItem" abstract="true" substitutionGroup="ifc:IfcRepresentationItem" nillable="true"/>`

<xs:complexType name="IfcGeometricRepresentationItem" abstract="true">

<xs:complexContent>

<xs:extension base="ifc:IfcRepresentationItem"/>

</xs:complexContent>

</xs:complexType>

```
ENTITY IfcGeometricRepresentationItem
```

ABSTRACT SUPERTYPE OF(ONEOF(IfcAnnotationFillArea, IfcBooleanResult, IfcBoundingBox, IfcCartesianPointList, IfcCartesianTransformationOperator, IfcCompositeCurveSegment, IfcCsgPrimitive3D, IfcCurve, IfcDirection, IfcFaceBasedSurfaceModel, IfcFillAreaStyleHatching, IfcFillAreaStyleTiles, IfcGeometricSet, IfcHalfSpaceSolid, IfcLightSource, IfcPlacement, IfcPlanarExtent, IfcPoint, IfcSectionedSpine, IfcShellBasedSurfaceModel, IfcSolidModel, IfcSurface, IfcTessellatedItem, IfcTextLiteral, IfcVector))

SUBTYPE OF (IfcRepresentationItem)**;**

END_ENTITY;